?Skin cancer refers to a group of tumors with different characteristics and origins, which can be categorized into 2 major groups: melanoma and nonmelanoma skin cancer. In recent decades, the incidence of skin cancer has risen in Spain, Europe, and worldwide.1–6 While there are several risk factors, the main cause is still exposure to ultraviolet radiation, especially when there is a history of high accumulated sun exposure and episodes of sunburn during childhood and adolescence.1,5,7 Consequently, a history of sunburn is one of the parameters most often used in epidemiological studies to assess sun exposure behaviors, especially in patients with melanoma.8

In Spain, knowledge and attitudes related to sun exposure habits and sun protection behaviors have been studied mainly in adolescents and in populations living near beaches along the eastern and southern seaboards of the Iberian penninsula.8–13 There is little data on this topic from the university population,12 and no validated data is available on the sun exposure habits of people living in the Canary Islands. Questionnaires are the instruments usually used to investigate health-related behaviors; they can be used in population studies and to assess the impact of interventions that have been implemented in the general population.9 Medical students are a group in which we can assess attitudes, knowledge, and behaviors in a population with a high level of knowledge about carcinogenesis, making them an ideal study population when our aim is to determine whether having such knowledge influences the individual's sun exposure habits and photoprotection behavior or has an impact on the frequency of sunburn.

In total, 286 of the 411 students in the course completed the questionnaire: 74 (59.2%) were first-year students, 129 (81.1%) were in their third year, and 83 (65.4%) were in the sixth year of their medical studies. Two participants failed to complete the questionnaire and the unanswered questions were treated as lost values.

The most significant finding in this study was the very high frequency of sunburn in this population, when one would expect that sunburn frequency would, at least, be lower in medical students than in the general population. Despite the lower sunburn frequency among students with more years of study, half of the final year students continue to report at least 1 sunburn every summer. Moreover, students’ attitudes and knowledge remain almost unchanged throughout their studies.

Using the same questionnaire in an adolescent population living in the Costa del Sol area, Fernández-Morano et al. observed a sunburn frequency of 74.4%.10 During the validation of this questionnaire in a population aged under 14 years living in southern Spain, this percentage was 43.3%,9 and a similar frequency (46.9%) was reported in a study carried out on the beach in the Costa del Sol area.8 Another study carried out on the beach in Valencia reported a history of sunburn in 70% of respondents, with a higher frequency among adolescents and young adults.13 This was is the first validated study on sun exposure habits carried out in the Canary Islands. The possibility of practically year-round sunbathing in our area would explain a greater sunburn frequency than in the population of the Iberian peninsula. In other studies in university students, Lopez-Ravello et al. observed a sunburn frequency of 88.2% in students of the University of Granada.12 Yurtseven et al. studied students attending the University of Istanbul, 39.6% of whom reported having a sunburn episode at least once in their lives.16 The authors of another study observed a lack of knowledge and incorrect sun exposure habits among students attending the Faculty of Physical Education and Sports Sciences at the University of Granada but did not investigate history of sunburn epidsodes.17

Both age and academic year showed an independent association in the multivariate analysis. The risk of sunburn decreased as the students advanced in their studies. This decline could be explained by the lack of maturity and scant awareness of the risk of disease among younger people.18 Another reason for the decline could be that as students advance in their studies, their medical knowledge increases and they become more aware of the medical facts, and place a greater value on their own health. Despite this, the percentage of sixth year students in our study who reported sunburn episodes was high.

In our study, male sex was associated with sunburns, but the data on this association in earlier studies in inconsistent.8,10,13 Our finding could be due to the fact that the women used more sunscreen and products that had a higher SPF. In a literature review on skin cancer prevention published by Stanton et al. in 2004, several of the articles included indicated that men and young people are at greater risk of sunburn. Those authors also noted that women were more knowledgeable about skin cancer and tended to exhibit more protective behaviors. This is in contradiction with the fact that women are more likely than men to perceive tanning as desirable,11,13 a finding confirmed in our study.

In our study, a low skin phototype was a protective factor, by contrast with the results of other studies in which phototypes I, II and III are compared with phototype IV.8 Probably students with phototypes I and II have suffered severe sunburn in the past and are more aware of the need for protective habits and measures, while individuals with higher skin phototypes do not make adequate use of sunscreens or use them to increase the length of exposure to the sun.11,19,20

In our study and in those mentioned above,8–13,16 the photoprotection measure most often used were topical sunscreens. The statement “It is worthwhile using sunscreen even though it stops me from tanning” was negatively associated with sunburn. The statement “I dislike high protection creams because they look unattractive” was positively associated with sunburn. These findings highlight the importance of developing cosmetically acceptable, high SPF topical sunscreens that are easy to apply and would facilitate adherence to sun protection measures in the general population.

The percentage of knowledge questions answered correctly was very high, and this did not vary across the 3 academic years. In spite of this, the students expressed positive attitudes toward sun exposure and reported inadequate use of photoprotection, a phenomenon that has already been described.13,19 The authors of a study of Australian adolescents concluded that a high level of knowledge is not related to the adequate use of photoprotection and that attempts to modify attitudes and behaviors in adolescents have limited success.21 The question with the lowest percentage of correct answers was perhaps the most specific: “Avoiding sun exposure when you are young (before 18 years of age) reduces the risk of skin cancer by 80%.” Prevention campaigns tend to focus on the overall risk of skin cancer and not emphasize that children and adolescents are the population in which the impact of exposure on the future of skin cancer is greatest.

The main limitation of our work is that the study population was geographically and sociologically delimited, so the data cannot be extrapolated to the population as a whole. Moreover, it was a cross-sectional study based on a questionnaire which, although specifically designed and validated for this type of study, may be susceptible to memory bias or a desire to provide socially desirable answers. Our work does show that a thorough knowledge of the risks of sun exposure and its relationship with skin cancer is not necessarily associated with proper preventive behaviors or a lower frequency of sunburn, even in a presumably sensitized population, such as a group of medical students including those who have completed 6 years of advanced studies and have studied skin disease.

Our findings, obtained in a selected population with the maximum possible knowledge about sun exposure, suggest that photoprotection campaigns should focus more on modifying attitudes than providing knowledge. To do this, they need to influence the population at a younger age and look for other possible strategies, such as using social referents (athletes, actors, or singers) as models.21 At the same time, the current aesthetic model needs to be modified because darker skin tone is still synonymous with beauty.

The authors declare that they have no conflicts of interest.